By Tom Ehrich

Most Americans don’t care who is Mayor of New York City. Heck, most New Yorkers don’t care, to judge by turnout in our recent mayoral primary.

But we do have a mayor — currently billionaire publisher Michael Bloomberg — and every now and then, it matters a lot whether our mayor is up to the job.

Crime sprees, terrorist attacks, labor strikes (such as sanitation workers), collapsing public schools, police behavior — in circumstances such as these, the mayor’s competence and character make a huge difference.

That difference means matters being handled well, and it means the public’s trust in both process and outcome. It isn’t enough to act wisely. The mayor also has to convince people he acted wisely on their behalf, not on behalf of some powerful interest group.

Thus, Mayor Bloomberg’s initiative to open the Grand Central Terminal area to major new development might be a wise decision for economic growth and tourism. But it is perceived as a gift to his “buddies” in the real estate development world.

The art of politics isn’t just being smart, wise and effective in the corridors of power. It’s also being transparent and even-handed, not secretive and PAC-bound, so that the resulting narrative isn’t just “I made the right decision,” but “I made the right decision on your behalf.”

Congress is failing badly in the “on your behalf” requirement. So is President Obama. When everything goes the bankers’ way, for example, people being abused by banks cry foul. So do those being out-maneuvered by banking lobbyists and lorded over by high-living bankers. They wonder if anyone cares about them.

Thus you get the failed candidacy of Lawrence Summers for Federal Reserve chairman. He might well have been the “smartest person in the room,” as he is said always to believe. But he was perceived as favoring bankers, and since bankers are out to get us, as the narrative goes, he couldn’t possibly be right for the job.

Another case in point: the NSA debacle, where truth dribbled out and spooks’ secrecy evidently mattered more to the president than our privacy.  

Thus the genius of Dwight Eisenhower, who as a five-star managed to convince men being sent to die that he cared about them, and, later, that he would do no less as President.

Thus the fatal flaw of George W. Bush, whose interest never seemed to extend beyond his country club pals. Or the Clinton legacy that Hilary will struggle to escape: at the end of the day, it’s all about me.

As the richest man in New York City, Bloomberg is impossibly far removed from the typical New Yorker. The narrative, though, is that because he doesn’t need special-interest largesse, there’s a chance he’ll remember “on your behalf.”